Combination therapy refers to the use of two or more HIV medications to treat HIV. According to TheBody.com, combination therapies are more effective at suppressing HIV than individual HIV drugs used alone. HIV drug classes attack HIV in different stages of the HIV life cycle. Using combination therapies that includes drugs from different classes ensures that HIV replication is inhibited at all stages of the virus's life cycle.
Two NRTIs and one NNRTI
According to TheBody.com, two nucleoside reverse transcriptase or NRTIs pills are taken together with one non-nucleoside reverse transcriptase or NNRTI to treat HIV infection. This combination is effective in lowering amounts of virus in the blood and in helping raise CD4 cell counts. Avert.org lists an example of NRTI and NNRTI combination therapy that is commonly used to treat HIV: Zidovudine and lamivudine, which are NRTIs, are used together with efavirenz, an NNRTI. NNRTIs work by blocking reverse transcriptase, an enzyme that HIV needs in order to replicate. Common side effects of NNRTIs include upset stomach, vomiting, skin rash, dizziness, tiredness, insomnia and headache. NRTIs are faulty versions of reverse transcriptase enzyme. When HIV uses an NRTI instead of a normal reverse transcriptase, virus replication is destroyed. Common side effects of NRTIs include headache, tiredness, dizziness, upset stomach, nausea and vomiting. Adverse side effects of NNRTIs and NRTIs include liver failure, kidney failure and pancreas problems.
Two NRTI and One PI
According to TheBody.com, a doctor may prescribe a combination of two NRTIs and one Protease inhibitor to be taken together to treat HIV infection. Indinavir+AZT+3TC drug combination is an example of combination therapy commonly used to treat HIV. Indinavir is a protease inhibitor, PI, whereas AZT and 3TC are NRTIs. PIs disable protease, a protein that HIV needs to replicate. Common side effects of PIs include diarrhea, nausea, vomiting, weakness and headache. Serious side effects of PIs include liver failure, kidney failure, diabetes and worsening of diabetes.
Multi-class Combination Therapy
According to U.S. Food and Drug Administration, multi-class combination therapy involves the combination of two or more anti-retroviral drugs into a single pill that is taken once a day. Multi-class therapies reduce the burden of taking multiple HIV medications. An example of a multi-class drug is Atripla. Atripla contains ingredients from different classes of antiretroviral drugs and is taken once a day. Common side effects of Atripla include dizziness, insomnia, rash, diarrhea, nausea, vomiting and weakness. Adverse side effects include severe depression, kidney failure, liver failure and osteoporosis.
